JP2003-272972A, JP2006-108380A, JP2003-272966A, JP3869183B, JP2006-338934A, JP2008-204985A, JP2002-353078A and JP2005-190885A propose an electric double-layer capacitor, a lithium-ion battery and the like as an energy storage cell which is quickly rechargeable and has a long charge/discharge cycle life.
An example is described with reference to FIG. 22. An energy storage cell 100 is an electric double-layer capacitor. The energy storage cell 100 includes an energy storage part for storing electric charges and a container 111 for containing the energy storage part.
The energy storage part is a laminated body composed of a positive electrode, a negative electrode and a separator interposed between the positive electrode and the negative electrode. The positive electrode and the negative electrode are composed of an electrode layer for storing electric charges and a collector layer through which electric charges are charged and discharged. The electrode layer is a polarizable electrode containing an electrolyte. A positive electrode terminal 112A whose polarity corresponds to that of the collector layer of the positive electrode is joined to the positive electrode. A negative electrode terminal 112B whose polarity corresponds to that of the collector layer of the negative electrode is joined to the negative electrode.
The electrode terminal 112 is formed of a material having good electrical conductivity and into a short rectangle form. A collector electrode having a corresponding polarity is joined to a base end part of the electrode terminal 112 located inside the container 111. A tip end part of the electrode terminal 112 is drawn out to the outside of the container 111. The container 111 is, for example, formed of a laminated film which is a resin film having a laminated structure. The container 111 is sealed after housing the energy storage part such that the tip end part of each electrode terminal 112 projects to the outside.
In the energy storage cell 100 of FIG. 22, the container 111 is composed of a pair of container parts which are so combined that recessed parts thereof face each other. In the energy storage cell 100, a chamber for housing the energy storage part is defined in the container 111 by the pair of recessed parts. The energy storage part is sealed in a state where the leading end side of each terminal 112 projects to the outside by thermally fusing flange parts surrounding the chamber to each other. The energy storage cell 100 includes a degassing valve 115 for suppressing an internal pressure of the container 111 to or below a predetermined level.
A withstand voltage of the single energy storage cell 100 as shown in FIG. 22 is about 3 to 5 V. A predetermined number of energy storage cells 100 are used by being connected in series to obtain a necessary power-supply voltage.
An energy storage module M100 constituted by a predetermined number of energy storage cells 100 is shown in FIG. 23. The energy storage cells 100 are arranged in a line in a thickness direction of the containers 111 to become an overlapping assembly. The electrode terminals 112 having different polarities are electrically connected between adjacent energy storage cells 100.